Apparatus for twisting an advancing strand



E. c. HARDESTY 2,926,482

APPARATUS FOR TWISTING AN ADVANCING STRAND March 1, 1960 Filed July 9, 1958 3 Sheets-Sheet l FIG. 2

INVENTOR. E. C. HAROEST) BY QC.

4 TTORNEV March 1, 1960 E. c. HARDESTY 2,926,482

APPARATUS FOR TWISTING AN ADVANCING STRAND Filed July 9, 1958 3 Sheets-Sheet 2 INVENTOR. E. C. HARDESTY A TTORNEV March 1, 1960 ac. HARDESTY APPARATUS FOR TWISTING AN ADVANCING STRAND 5 Sheets-Sheet S Filed July 9, 1958 INVENTOR'. E. 0. HA RDESTY BY (La.

4 TTORNEV APPARATUS FOR TWISTING AN ADVANCING STRAND Edwin C. Hardesty, Baltimore, Md., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Application July 9, 1958, Serial No. 747,528

6 Claims. (Cl. 57-11) The present invention relates generally to apparatus for imparting an axial twist to an advancing strand, and more particularly to apparatus for imparting a predetermined axial twist to a length of cordage being wound into a helix on a rotating and longitudinally moving mandrel and for terminating the helix-winding and twisting operations when a predetermined amount of cordage has been wound.

in the telephone field and in the field of various electrical appliances, it has been the practice in certain applications to utilize spring or retractile cords, a common example of which is the cord extending between the base and the headpiece of a telephone hand set. The spring cords are formed so that the major portion thereof is in the form of a compact helical coil, which will lengthen when slight tension is applied thereto but will return to its compactly coiled position when the tension is removed.

One method of forming spring cords is disclosed genorally in US. Patent No. 2,413,715, issued on January 7, 1947, to A; R. Kemp et al. The method therein disclosed includes the step of winding a length of conducting cordage, jacketed with an' elastic vulcanizable material, in a helix on a rotating and longitudinally moving mandrel while imparting a predetermined axial twist to the cordage being wound. The axially twisted helix is clamped to the mandrel and is then heat treated to cure the jacketing material and form the desired spring cord. The apparatus of the present invention is particularly useful for simultaneously coiling and twisting a predetermined length of a jacketed conductingcord into a compact, axially twisted helix as a step in the manufacture of spring cords under the general method just described.

An object, therefore, of the present invention is to provide new and improved apparatus for imparting an axial twist to an advancing strand.

Another object of the invention is to provide apparatus for imparting a predetermined axial twist to a length of cordage being wound into a helix on a rotating and longitudinally moving mandrel.

A further object of the invention is to provide means for terminating the helix-winding and twisting operations I when a predetermined amount of cordage has been wound.

An apparatus for imparting an axial twist to an addesigned to retain the strand, preferably a V-shaped" ,nited States Patent 2 groove within which the strand is wedged by the companion roller as it advances between the rollers.

The strand may conveniently be formed with an enlarged portion (such as a molded grommet at the end of a telephone cord) near a point therealong where it is desired to terminate a strand-working operation (such as a helix-winding operation). In this case, means are provided, responsive to the advancement of the enlarged portion of the strand toward the rollers, for separating the rollers to allow the enlarged portion of the strand to pass therethrough. Further, means are provided, responsive to the position of the enlarged portion of the strand, for terminating the strand-working operation when the enlarged portion of the strand is located a desired distance from the strand-working apparatus.

For these purposes, the rollers may be mounted on a rotatable support and a strand guide may be provided, mounted between the support and the rollers, for rotation with the support. The strand guide has a restricted guide aperture, is movable along the line of advancement of the strand, and is normally biased toward the support. The enlarged portion of the strand engages and catches in the restricted aperture of the guide so as to move the guide toward the rollers and separate them. The rotation of the guide with the support operates to twist the strand caught in the restricted aperture.

Other objects and advantages of the invention will appear from the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. 1 is a top plan view of a twisting apparatus embodying the invention, shown in conjunction with a helixwinding apparatus with which it may be used;

Fig. 2 is a front view of the apparatus illustrated in Fig. 1;

Fig. 3 is an enlarged top view of the twisting apparatus illustrated in Fig. 1, with portions broken away to reveal structural details;

' Fig. 4 is a view similar to Fig. 3, but illustrating certain elements of the apparatus in moved, end-of-winding positions, and

Fig. 5 is an enlarged rear view, partially in vertical section, taken generally along the line 55 of Fig. 3 in the direction of the arrows, the vertical section being through portions of a pair of twisting rollers in order to illustrate a combined cordage guide and operation-terminating assembly.

Referring now in detail to the drawings, and in particular to Figs. 1 and 2, the improved twisting and operationterminating assembly, designated generally by the numeral 10, is shown in conjunction with a helix-winding apparatus with which it may be used. A length of strand material, such as a jacketed cord designated generally by the numeral 11, is advanced through the twisting and operation-terminating assembly 10'into winding engagement with a rotating and longitudinally moving mandrel 12. The specific apparatus shown for rotating and moving the mandrel 12 forms no part of the instant invention and will be described only briefly.

A preferred form of apparatus for rotating the mandrel, moving the same longitudinally in predetermined synchronism with the speed of rotation, supporting the mandrel during movement thereof, guiding the cordage to the mandrel, and forming the cordage as it is wound onto a uniform, tight helix about the mandrel is described in detail in a copending application Serial No; 738,439, filed on May 28, 1958, in the joint names of applicant and D. L. Myers.

While the apparatus disclosed in the copending application just mentioned is highly preferable in many respects, a diiferent apparatus is illustrated in Figs. 1 and 2, which apparatus is functional and simpler to describe.

The mandrel 12 is first positioned across a pair of mandrel supports 1313 and is then connected at one end to a rotatable chuck 14 for eventual rotation and longitudinal movement therewith.

A lead end 16 of a cord 11 to be wound is then fastened to the left-hand end (Fig. l) of the mandrel 12. A cord age clamp, designated generally by the numeral 17, is received on the mandrel 12. The clamp 17 is designed to slide on the mandrel 12 during the winding operation but to be tightened on the mandrel in abutment with the lastwound convolution of the cord when the winding operation is completed to clamp the same to the mandrel. The chuck 14 and the Cordage clamp 17 are shown and described fully in the earlier-mentioned copending application.

The chuck 14 is keyed to one end of a rotatable shaft 18, which is supported in a bearing 19 and is driven by a suitable drive motor 21. The motor 21 and the bearing 1 are mounted on a carriage 22 for reciprocating movement to the left and right as viewed in Figs. 1 and To accomplish this reciprocating movement, the motor shaft 18 is formed with a worm 23, which meshes with a worm gear 24, seen in Pig. 2. The worm gear 24 is keyed to an axle 26 and a pair of drive wheels 22-27 are keyed to the ends of the axle 26 so that rotation of the worm 23 operates to rotate the drive wheels 2'72'7', which are designed to roll along a pair of tracks 2ll-23.

The axle 26 is journaled for rotation near its ends in a pair of support bearings 29-29, which are connected to the carriage 22 and extend upwardly therefrom, so that movement of the wheels 27-27 along the tracks 2S-2$ causes corresponding movement of the carriage 22 and the elements secured thereto including the rotating chuck 14 and the mandrel 12. A pair of idler wheels i-31 are likewise mounted to roll along the tracks 23-28 and are keyed to a pair of stub shafts 32-452, which are journaled in a pair of bearing supports 3333 secured to and extending upwardly from the carriage 22.

The motor 21 is rotatable in either direction and rotation in a clockwise direction, according to the arrow in Figs. 1 and 2: (1) rotates the mandrel 12 in a clockwise direction to wind the cord 11 thereon; and (2) rotates the worm gear 24 and the connected drive wheels 2727 in a counterclockwise direction, as viewed in Fig. 2, to move the carriage 22 and the elements connected thereto from right to left in order to move the mandrel 12 longitudinally and enable winding of the cordage 11 thereon in a helix. The pitch of the worm 23, the size of the worm gear 24, and the diameter of the drive wheels 27-27 are regulated so that the longitudinal movement of the mandrel 12 is synchronized with the speed of rotation thereof in order to wind the cordage in a helix of the desired pitch. Preferably, the longitudinal speed is set approximately equal to one cord-diameter for each revolution of the mandrel so that the cordage is wound in a closely packed helix.

When the coiling operation has been completed, the motor 21 is stopped and preferably braked, the trailing end of the cordage 11 is clamped to the mandrel 12 with the clamp 17, and then the wound mandrel is removed from the chuck 14 and the left mandrel support 13 for transportation to a heat-treating oven (not shown). The motor 21 is then rotated in the opposite direction to reciprocate the carriage 22 and the chuck 14 carried thereby from left to right, as viewed in Figs. 1 and 2, back to the starting positions thereof, whereupon another mandrel may be secured to the chuck s4 and the operation repeated.

The twisting and operation-terminating assembly 16 is best seen in Figs. 3, 4 and 5 and includes a pair of opposing rollers 34 and 36 mounted so that the cord 11 advances between the peripheries thereof. The rollers 34 and 36 are designed for revolution, as a unit, about the' longitudinal axis of the cord 11 advancing therebetween to twist the advancing cord about its longitudinal axis.

Each of the rollers 34- and 36 is mounted for rotation between the upper ends (Figs. 3 and 4) of a pair of supporting arms 3737, each of which is pivotably connected at its lower end between a pair of supporting lugs 38-36. The lugs 38-38 are fixed to the upper surface (Figs. 3 and 4) of a rotatably pulley 39. The lugs 33-38 are positioned, as best seen in Fig. 5, so that the rollers 34 and 36 are mounted on opposite sides of the center of the pulley 3's with the centers of their peripheries in alignment. The lugs 38-38 are further positioned so that the rollers 34 and 36 may be pivoted into peripheral contact with each other substantially in line with the center of the pulley 39.

The pulley 39 is formed with a central aperture 41 through which the cord 11 advances with a relatively large clearance, from bottom to top as viewed in Figs. 3 and 4, the cord 11 then passing between the opposing peripheries of the rollers 34 and 36. As best seen in Fig. 5, the periphery of the roller 34 is formed with a V -shaped groove 42 designed to retain the cord 11 therein as it advances therepast. The companion roller 36 is thinner than the grooved roller 34 and is formed with a fiat periphery so that the pulley 36 may enter the V-groove 42 to the point where its fiat periphery engages the cord 11.

A pair of biasing springs 43-43 are secured between one of the supporting arms 3737 associated with each of the rollers 34 and 36, and the pulley 39. The springs 43-43 operate to bias the rollers 34 and 36 toward the pulley 39, and thus toward each other, to a position where the opposing peripheries of the rollers 34 and 36 engage the advancing cord compressively.

A. second drive motor 44 (Figs. 1 and 2) is mounted on a table 46, which supports the entire apparatus, and is designed to rotate the pulley 39 in order to revolve the rollers 34 and 36 carried thereby, as a unit, about the longitudinal axis of the cord 11 advancing 'therebetween. For this purpose, a driving belt 4'7 passes around both the pulley 39 and an output pulley 48 connected to a shaft 49 of the motor 44.

The biasing springs 43-43 are made sufficiently strong so that the opposing rollers 34 and 3d engage the cord 11 with sufiicient compressive force to twist the cord 1.1 advancing therebetween about its longitudinal axis by the revolution of the rollers. The peripheries of the rollers 34 and 36 are preferably lined with a frictional material, such as a hard rubber surface for polyvinyl-chloride jacketed cords, to assist in the, twisting engagement and prevent slippage.

The mating, V-grooved and flat-periphery structure of the rollers 34 and 36 is highly preferred since, with this design, the advancing cord 11 is wedged into the V-groove 42 to provide a clamping action as well as a seat for the cord as it advances between the rollers so that the twisting proceeds without slippage but permits advancement of the cordage due to the rotatable mountings. Further, the V-grooved design enables the twisting of cords having a wide range of diameters, whereas a design such as opposing arcuately grooved peripheries would not be feasible to twist cords of different diameters. Opposing flat peripheries would be operable in certain cases; however, higher spring tensions would be required to prevent slippage and relatively pliable cords, such as polyvinyl-chloride jacketed cords, might be unduly deformed.

The speed of the motor '44 is synchronized, for the purposes described in the Kemp et al. patent, in any wellknown way with that of the motor 21 so that the rate of twisting is precisely regulated with respect to the speed of advancement of the cord 11. It would also be possible to drive the pulley 39, through suitable gearing, from the motor 21 to accomplish the same result. As seen in Figs. 1 and 2, the shaft 49 of the motor 44 is journaled ina bearing block 51 mounted on the table 46 and, as

best seen in Figs. 3 and 4, an annular hub 52 of the pulley 39 is similarly journaled in a bearing block 53.

A cordage guide, forming a part of the operationterminating assembly and designated generally by the numeral 56, is also provided and is best seen in Figs. 3, 4 and 5. The cordage guide 56 is normally mounted between the pulley 39 and the rollers 34 and 36 for movement along the line of advancement of the cordage 11 and also for rotation with the pulley 39.

For these purposes, a pair of supporting rods 57-57 are slidably received within bores formed in the pulley 39 and are secured between the guide 56 and a circular end plate 58, which is mounted coaxially below the pulley 39 as seen in Figs. 3 and 4. The end plate 58 is formed with an enlarged central aperture 59, the cord 11 advancing through the aligned, relatively large apertures 59 and 41 to the guide 56.

A pair of biasing springs 61-61 are mounted about the supporting rods 57-57, extending between the under surface (Figs. 3 and 4) of the pulley 39 and the upper surface of the end plate 58, and are designed to exert a relatively light biasing action forcing the end plate 58 away from the pulley 39 so that the guide 56 normally rides on the upper surface of the pulley 39.

As best seen in Fig. 5, the guide 56 includes a pair of jaws, designated generally by the numerals 62 and 63, pivotably connected by a pivot pin 64. The jaw 62 is formed at one end of a thin L-shaped lever 66 while the jaw 63 is formed on a thin block 67, the lever 66 being mounted by means of the pivot pin 64 on the surface of the block 67. The guide rods 57-57 described earlier are secured near the lower end (Fig. 5) of the block 67 so that the entire guide assembly 56 is movable toward and away from the pulley 39. I

The jaws 62 and 63 are formed with opposing, arcuate, nearlysemicircular seats 63-68 and bell-mouthed entrance apertures 69-69 communicating with the seats 68-68. A spring 71 is connected between the block 67 and the lever 66 to urge the lever in a clockwise direction, as viewed in Fig. 5, about the pivot pin 64 and into contact with a fixed stop 72 extending upwardly from the block 67. This is the normal position of the guide and, in such position, a restricted strand-guiding aperture is defined by the opposing arcuate seats 68-68 of the jaws 62 and 63. v

The diameter of the restricted aperture, as illustrated in Fig. 5 is just sufiicient to pass normal-diameter portions of the cord 11 and guide the same to the rollers 34 and 36. The guide-biasing springs 61-61 are made strong enough to maintain the guide 56 against the surface of the pulley 39, against the force of friction due to normal-diameter portions of the cord 11 passing through the restricted guide aperture.

Before the start of each winding operation, the lead end 16 (Fig. l) of the cord 11 is threaded through the relatively large, aligned apertures 59 and 41. The aperture 41 is made sufiiciently large that the lead end (which may be enlarged) of the cord 11 can pass therethrough in a line completely above (Fig. 5) the jaws 62. and 63 so as to bypass the jaws. In-this position, a normaldiameter portion of the cord 11 may then be forced downward, as viewed in Fig. 5, into the bell-mouthed entrance apertures 69-69, the lever 66 pivoting open, against the action of the spring 71, to allow the cord to pass into position between the arcuate seats 68-68 defining the restricted guide aperture. I

When the cord 11 has been inserted into the guide aperture, the spring 71 pivots the lever 66 back to its closed or guiding position, which is that depicted in Figs. 3 and 5. An adjustable stop 73 extends fromthe jaw 63 and serves to limit the pivoting movement of the lever 66 to an amount just sufficient to permit the insertion of the cord 11.

The cord 11 is provided with an enlarged end portion gear a .po tt'the l n whe i i jqe i s .t s m a s the helix-winding operation. In the preferred embodiment shown, for manufacturing spring cords-for telephone hand sets, a long length of jacketed cordage 11 comprising three individually insulated conductors 76-76 with an extruded polyvinyl chloride jacket 77 is cut to desired cord-lengths before the coiling operation.

Short lengths of the jacket 77 are then stripped from the ends of the cord to expose the insulated conductors 76-76, and a. number of conductive tips 78-78 are secured, one to the end of each of the conductors 76-76. A pair of grommets, the trailing one of which is designated in the drawings generally by the numeral 79, of plastic material such as polyvinyl chloride, are next secured, e.g. by molding, to thecord 11 at each end of the stripped portion of the jacket.

An important advantage of the present invention is that the complete cord can be formed before coiling, a relatively easy operation, and then wound, thus eliminating the necessity of winding a running length of cordage and then cutting and preparing the ends of the cord after the coiling operation.

The cord 11 is wound on the mandrel 12 until the end grommet 79 advances through the aperture 59 in the end plate 58, through the central aperture 41 of the pulley 39, and into contact with a pair of enlarged, tapering, curved surfaces 80-80, communicating with the seats 68-68, formed on the under side (Figs. '3 and 4) of the jaws 62 and 63, and together defining a frustoconical recess. Upon further advancement of the cord 11 by the rotating mandrel 12, a fruso-tconical lead sur face 81 of the grommet 79 is wedged into the frustoconical recess defined by the surfaces 80-80. This action operates to spread the jaws 62 and 63 a slight distance apart, as limited by the adjustable stop 73. This spreading movement is designed to the slight (only enough 'to allow sidewise insertion of the cord 11 at the start of the operation) and the grommet 79 is too large to .be pulled into the now-enlarged, but still-restricted, guide aperture defined by the arcuate seats 68-68. Obviously, the shape of the enlarged surfaces 80-80 is dictated by the shape of the enlarged portion of the cord, the surfaces 80-80 being designed to receive the enlarged portion for rotation therewith.

The wedging reception of the grommet with the guide 56 operates, upon further advancement of the cord 11, to move the entire guide 56, against the action of the biasing springs 61-61 toward the rollers 34 and 36. The moving guide 56 is designed to engage [and separate the rollers 34 and 36, against the action of their biasing springs 43-43,'to permit the guide 56 and the grommet 79 wedged therein to pass between the rollers.

As previously noted, the entire guide assembly 56 is rotatable with the pulley 39 so that the guide assembly 56 maintains the fixed attitude seen in Fig; 5 toward the rollers 34 and 36, regardless of the rotational position of thepulley 39. In order to facilitate the spreading of the rollers 34 and 36, the guide assembly 56 is formed as narrow as possible so as not to require undue spreading of the rollers, and the upper surfaces'of the jaws 62 and 63 are provided with tapered camming surfaces 82-82 of resilient material, such as Teflon, to facilitate the spreading of the rollers and to provide shock resistance. N

The tapered,leading surface 81 of the grommet 79 is wedgeinto the frustoconical aperturedefined by the tapered surfaces 80-80, which surfaces are preferably lined with a frictional material such as hard rubber and are lightly knurled to retainthe' grommet 79 tightly. This engagement permits continued twisting of the cordage ll at the same-rate, even though the twisting rollers 34and 36 have been separated, the twistingbeing nowjaccomplished by the tight, wedging connection between j'the grommet 79 and the guide 56. 1 In this manner, the coiling operation continues with the elements moving from' their normal, coiling positions 7 illustrated in Fig. 3 to their end-of-coiling positions illustrated in Fig. 4.

A limit switch 83 isprovided, having an actuator 84 disposed in the path of movement of the circular end plate 58. The switch 83 is adjustably mounted on a stationary support, such as the bearing block 53, and its position is adjusted so that the actuator 84 will be moved by the plate 58 to reverse the contacts of the switch 83 when the grommet 79 is located a desired distance from the mandrel 12 at the. end of the coiling operation. In this way, a designed straight length of cordage is left extending from the end of the fully wound mandrel,

The reversal of the contacts of the switch 83 results in a de-energization of the driving motors 21 and 44 to terminate the coiling and twisting operations at the desired point. Preferably, a brake (not shown) is also operated to positively stop these motions substantially simultaneously with the closure of the contact of the switch 83.

Operation In operation, the chuck 14 is originally positioned slightly to the right of the position illustrated in Fig. l, and a mandrel 12 is inserted across the mandrel supports 13-13 and connected to the chuck 14. The lead end 16 of a cord 11 to be wound is next threaded through the aligned apertures 59 and 41 (Fig. 3), bypassing the upper edges (Fig. of the jaws 62 and 63, is then threaded between the rollers 34 and 36, and is finally secured to the lead end (Fig. l) of the mandrel 12. The portion of the cord 11 opposite to the guide 56 is then pushed downward (Fig. 5) into the restricted guide aperture defined-by the opposing arcuate seats 68-68. At this time, the rollers 34 and 36 and the guide 56 assume their winding positions, as depicted in Figs. 3 and 5, under the influence of the biasing springs 43-43, 61-61 and 71.

The drive motors 21 and 44 are then started substantially simultaneously. the motor 21 operating to rotate the mandrel 12 and move the same longitudinally in order to wind the cord 11 in a helix along a portion of the length of the mandrel, and the motor 44 operating to rotate the pulley 39 so as to revolve the rollers 34 and 36 connected thereto, as a unit, about the longitudinal axis of the cord 11 in order to impart the predetermined axial twist to the cord as it advances to the mandrel. The helix-winding operation proceeds in this manner, the mandrel 12 moving from right to left as viewed in Figs. 1 and 2, until the grommet 79 engages and catches in the restricted aperture of the cordage guide 56, the leading surface 81 of the grommet 79 being wedged into the ctanical recess defined by the tapered, frictional surfaces 8 -80.

Upon further advancement of the cord 11 by the rotating mandrel 12, the guide 56 is pulled toward the mandrel 12, against the action of the biasing springs 61-61, to the position illustrated in Fig. 4, wherein the guide 56 has moved past the rollers 34 and 36. During this movement, the camming surfaces 82-82 of the guide 56 spread the rollers 34 and 36 apart, against the action of their biasing spring 43-43, to permit the entire guide 56 to pass therebetween'toward the mandrel 12.

The cord. 11 continues to be twisted due to the wedging engagement of the grommet 79 with the tapered, frictional surfaces 80-80 of the guide 56. When the grommet, 79 is positioned a desired distance away from the mandrel 12, the circular end plate 58 strikes the actuator 84 of the limitswitch 83 to de-energize the motors 21 and 44, and preferably to apply a brake (not shown) to stop the coilling and twisting. operations. In this manher, and because of the adjustability of the switch 83, exactly the desired length of the cord 11 is wound on the mandrel and a predetermined straight length of. the cord, including at least the grommet 79, protrudes from the helix.

The grommet 79 may then be detached from the guide 56 and secured by means of the end clamp 17 (Fig. 1) to the mandrel 12. The fully wound mandrel is then detached from the chuck 14 and withdrawn from the lefthand mandrel support 13 for eventual conveyance to a heat-treating operation.

The rollers 34 and 36 and the guide 56 return to their original positions (Fig. 3) under the influence of their associated biasing springs. The motor 21 is energized in the opposite direction to reciprocate the carriage 22 and the chuck 14 carried thereby back to their initial positions, whereupon another mandrel may be inserted across the mandrel supports 13-13 and connected to the chuck 14 to enable the winding of another cord by a repetition of the operation.

It will be manifest that this invention is not limited to the specific details described in connection with the above embodiment of the invention, and that various modifications may be made without departing from the spirit and scope thereof.

What is claimed is:

1. Apparatus for imparting a predetermined axial twist to a length of cordage being wound into a helix on a rotating and longitudinally moving mandrel, which comprises a rotatable pulley having a central aperture through which the cordage may advance, a pair of support members opposingly and pivotably mounted on one side of said pulley, a pair of rollers mounted one on each of said support members, at least one of said rollers having a peripheral groove designed to retain the cordage as it advances therepast, said support members and rollers being so arranged that the cordage may advance between the peripheries of said rollers in a line with the center of said pulley, means for rotating said pulley in predetermined synchronism with the speeds of rotation and longitudinal movement of the mandrel in order to revolve said rollers as'a unit about the longitudinal axis of the cordage advancing therebetween, and means for biasing said pivotably mounted support members toward said pulley so that the opposing peripheries of said rollers engage the advancing cordage with sufiicient compressive force to twist the advancing cordage about its longitudinal axis by the revolution of said rollers with said pulley.

2. Apparatus for imparting an axial twist to a strand being advanced to a strand-working apparatus, the strand having an enlarged portion near the point therealong where it is desired to terminate the strand-working operation; which apparatus comprises a pair of rollers mounted so that the strand advances between the peripheries thereof, means for revolving said rollers as a unit about the longitudinal axis of the strand advancing therebe: tween, means for biasing said rollers relatively together so that their peripheries engage the advancing strand with sufiicient compressive force to twist the strand about its longitudinal axis by the revolution of said rollers, means responsive to the advancement of the enlarged portion of the strand toward said rollers for separating said rollers against the action of said biasing means to allow the enlarged portion to pass therethrough, and means responsive to the position of the enlarged portion of the strand for terminating the strand-working operation when the enlarged portion is located a desired distance from the strand-working apparatus.

3. Apparatus for imparting an axial twist to a strand being advanced to a strand-working apparatus, the strand having an enlarged portion near the point therealong where it is desiredto terminate the strand-working operation; which apparatus comprises a rotatable support, a pair of rollers mounted on said support so that the strand advances between the peripheries thereof, means for rotating said support so that said rollers revolve as a unit about the longitudinal axis of the strand advancing therebetween, means for biasing said rollers relatively together so that their peripheries ngage the advancing strand with sufficient compressive force to twist the advancingstrand about its longitudinal axis by the revolution of said rollers with said. support, a strand guide mounted between said support and said rollers for rotation with said support and also for movement along the line of advancement of the strand, said guide having a restricted guide aperture, means for biasing said guide toward said support, the enlarged portion of the strand engaging and catching in the restricted aperture of said guide so as to move said guide against the action of said guidebiasing means toward said rollers and the strand-working apparatus, said guide being designed to pass between said rollers and separate them against the action of their associated biasing means, the rotation of said guide with said support operatingto twist the strand caught in the restricted aperture, and means responsive to a predetermined amount of movement of said guide to terminate the strand-working and twisting operations when the enlarged portion of the strand is located a desired distance from the strand-working apparatus.

4. Apparatus for imparting a predetermined axial twist to a length of cordage being wound into a helix on a rotating and longitudinally moving mandrel, the cordage having an enlarged portion near a point therealong where it is desired to terminate the helix-winding operation; which comprises a rotatable pulley having a central aperture through which the cordage may advance, a pair of support members opposingly and pivotably mounted on one side of said pulley, a pair of rollers mounted one on each of said support members, at least one of said rollers having a peripheral groove designed to retain the cordage as it advances therepast, said support members and rollers being so arranged that the cordage may advance between the peripheries of said rollers in a line with the center of said pulley, means for rotating said pulley in predetermined synchronism with the speeds of rotation and longitudinal movement of the mandrel in order to revolve said rollers as a unit about the longitudinal axis of the cordage advancing therebetween, means for biasing said pivotably mounted support members toward said pulley so that the opposing peripheries of said rollers engage the advancing cordage with sulficient compressive force to twist the advancing cordage about its longitudinal axis by the revolution of said rollers with said pulley, a cordage guide mounted between said pulley and said rollers for rotation with said pulley and also for movement along the line of advancement of the cordage, said guide having a restricted guide aperture, means for biasing said guide toward said pulley, the enlarged portion of the cordage engaging and catching in the restricted aperture of said guide so as to move said guide against the action of said guide-biasing means toward said rollers and the mandrel, said guide being designed to pass between said rollers and separate them against the action of their associated biasing means, the rotation of said guide with such pulley operating to twist the cordage caught in the restricted aperture, and means responsive to a predetermined movement of said guide to terminate the helix-winding and twisting operations when the enlarged portion of the cordage is located a desired distance from the mandrel.

5. Apparatus for imparting an axial twist to a strand being advanced to a strand-working apparatus, the strand having an enlarged portion near the point therealong where it is desired to terminate the strand-working operation; which apparatus comprises a rotatable support, a pair of rollers mounted on said support so that the strand advances between the peripheries thereof, means for rotating said support so that said rollers revolve as a unit about the longitudinal axis of the strand advancing therebetween, means for biasing said rollers relatively together so that their peripheries engage the advancing strand with sulficient compressive force to twist the advancing strand about its longitudinal axis by the rotation of said rollers with said support, a strand guide mounted between said sup port and said rollers for rotation with said support and 16 also for movement along the line of advancement of the strand, means for biasing said guide toward said sup port, the strand guide including a pair of jaws relatively movable toward and away from each other and having opposing arcuate seats which together define a restricted strand-guiding aperture, means for biasing the jaws relatively together so that normal-diameter portions ofthe strand are retained within the restricted aperturosfor advancement therethrough, the jaws being movedrelatively apart to permit sidewise insertion of the strand into the. restricted aperture at the start of a strand-working operation, means for limiting the movement apart to substantially that amount necessary to permit insertion of the strand, the jaws of said strand guide being further provided with enlarged surfaces communicating with the arcuate seats and facing the advancing strand, the enlarged surfaces being so constructed that theenlarged portion of the strand wedges tightly therein, the jaws moving apart against their associated biasing means a small distance limited by said limiting means, the engagement of the enlarged portion of the strand with said guide operating to move said guide against the action of said guide-biasing means toward said rollers and the strand-working apparatus, said guide being designed to pass between said rollers and separate them against the action of their associated biasing means, the rotation of said guide with said support operating to twist the strand wedged against the enlarged surfaces, and means responsive to a predetermined movement of said guide to terminate the strand-working and twisting operations when the enlarged port-ion of the strand is located a desired distance from the strand-working apparatus.

6. Apparatus for imparting a predetermined axial twist to a length of cordage being wound into a helix on a rotating and longitudinally moving mandrel, the cordage having an enlarged portion near a point therealong where it is desired to terminate the helix-winding operation; which apparatus comprises a rotatable pulley having a central aperture through which the cordage may advance, a pair of support members opposingly and pivotably mounted on one side of said pulley, a pair of rollers mounted one on each of said support members, said support members and rollers being so arranged that the cordage may advance between the peripheries of said rollers in a line with the center of said pulley, a first one of said rollers being formed with a V-shaped peripheral groove in which the strand is retained as it advances therepast, the oompanion roller being constructed so that its periphery may enter the V-shaped groove to engage the strand retained therein, means for rotating said pulley in predetermined synchronism with the speeds of rotation and longitudinal movement of the mandrel in order to revolve said rollers as a unit about the longitudinal axis of the cordage advancing therebet-ween, means for biasing said pivotably mounted support members toward said pulley so that the periphery of the companion roller wedges the rand into the V-shaped groove of the first roller and the advancing strand is effectively clamped between said rollers as it advances therebetween for twisting about its longitudinal axis by the rotation of said rollers with said pulley, a cordage guide mounted between said pulley and said rollers for rotation with said pulley and also for movement along the line of advancement of the cordage, means for biasing said guide toward said pulley, said cordage guide including a pair of jaws relatively movable toward and away from each other and having opposing arcuate seats which together define a restricted cordage-guiding aperture, means for biasing the jaws relatively together so that normal-diameter portions of the cordage are retained within the restricted aperture for advancement therethrough, the jaws being moved relatively apart to permit sidewise insertion of the cordage into the restricted aperture at the start of a helix-winding and twisting operation, means for limiting the movement apart to substantially that amount necessary to permit insertion 11' of the cordage, the jaws of said'cordage guide being further provided with enlarged surfaces communicating with the arcuate seats and facing the advancing cordage, the enlarged surfaces being so constructed that the enlarged portion of the strand wedges tightly therein, the jaws moving apart against their associated biasing means a small distance limited by said limiting means, the engagernent of the enlarged portion of the cordage with said guide operating to move said guide against the action of said guide-biasing means toward said rollers and the mandrel, said guide being designed to pass between said rollers and havinga tapered camrning surface of resilient material designed to separate said rollers against the action of their associated. biasing means, the rotation of 12. a said guide with said pulley operating to twist-the strand wedged against theenlarged surfaces, and means responsive to a predetermined movement of said guide to terminate the helix-winding and twisting operations when the enlarged portion of the cordage is located a desired distance from the mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 919,309 Blessing Apr. 27, 1909 FOREIGN PATENTS 128,914 Great Britain June 11, 1919 

